Release notes at https://blog.kitware.com/cmake-3-10-0-available-for-download/
- Support for building CMake itself with C++98 compilers was dropped. CMake is now implemented using C++11.
Use C++11 then. This has no effect on amd64, x86 where clang was already
the base compiler, with C++11 support, but does affect PowerPC and others.
PR 224721